Statement Of Cash Flows [Abstract]
| Concept | 
                                    
                                        2021-01-01 to 2021-12-31  | 
                            
                                
                                    
                                        2020-01-01 to 2020-12-31  | 
                            
                        
|---|---|---|
| Statement of cash flows [abstract] | ||
| Cash flows from (used in) operating activities [abstract] | ||
| Adjustments for interest expense | 
                                        
                                             
                                                445,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                229,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for interest income | 
                                        
                                             
                                                249,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                440,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) operations before changes in working capital | 
                                        
                                             
                                                3,420
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                296,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for decrease (increase) in trade and other receivables | 
                                        
                                             
                                                117,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                268,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for increase (decrease) in trade and other payables | 
                                        
                                             
                                                1,792
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1,069
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) investing activities [abstract] | ||
| Purchase of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets | 
                                        
                                             
                                                365,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                58,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Purchase of investments other than investments accounted for using equity method | 
                                        
                                             
                                                19,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                203,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Proceeds from sales of investments other than investments accounted for using equity method | 
                                        
                                             
                                                -
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                155,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     |